查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryAlthough numerous poly(ethylene glycol) (PEG)-based bioadhesives have been developed and commercialized for various biomedical applications, their biocompatibility and bioactivity performances are generally lacking. In addition, the development of adhesive hydrogels with rapid gelation and high tissue adhesion are desirable to promote the surgical procedures and enhance patient compliance. To overcome these problems, we designed a series of chemically crosslinked gelatin-PEG adhesive hydrogels (GP) through the enzymatic crosslinking reaction of horseradish peroxidase (HRP). The resultant GP hydrogels were rapidly formed in situ within seconds to minutes after injection, and their mechanical as well as adhesive properties were adjustable in a wide range by changing the molecular weight and content of PEG. Notably, the hybrid hydrogels composed of 20 kDa PEG with ratio of 2.5/7.5 gelatin/PEG (wt/wt) showed 11 times greater tissue adhesiveness than commercially available fibrin glues. From in vitro cell studies, the hybrid adhesive hydrogels are nontoxic and improve the cell proliferation. Importantly, the hydrogels exhibited excellent hemostatic capability and accelerated the wound healing in vivo, compared to fibrin glue. These injectable GP hydrogels effectively improved the tissue adhesiveness and bioactivity of PEG-based adhesives, and hold great potential for hemostatic and wound healing treatments.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe effects of temperature, hydrogen partial pressure, and time in catalytic reduction step on carbon nanotube growth in a catalytic methane decomposition have been investigated for Mo-Fe/MgO catalysts. The results show that the reduction conditions of the catalyst affect the crystal structure of the metal formed on the catalyst surface and the growth mechanism of the generated carbon nanotubes. Both diameter distribution and crystallinity of the CNTs increased with the increase of reduction temperature in the range of 400 to 800 °C. The optimal reduction temperature with the maximum carbon yield was found to be 500 °C. The increase of hydrogen partial pressure and reduction time increased the CNT diameter distribution, and the optimal hydrogen partial pressure and reduction time with maximum carbon yield were found to be 0.1 atm, 60 min and 0.3 atm, 5 min, respectively. In the different combination of hydrogen partial pressure and reduction time for maximizing carbon yield, the CNT average diameter did not have a significant change, while the CNT crystallinity showed opposite trends depending on the methane decomposition reaction time. Ultimately, it was confirmed that the Mo-Fe/MgO catalyst can change the properties of CNTs produced through control of reduction conditions.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistrySelenium is a harmful trace element emitted during the combustion process of coal-fired power plants. Most of the selenium is enriched in the downstream wet flue gas desulfurization system (WFGD). This study found that S2O82- is the most important factor affecting the oxidation of selenite. In the process of simulating slurry oxidation of selenite to selenate, the presence of S2O82- can increase the oxidation rate of selenate from about 50% to about 80%. At the same time, this study also considered the influence of selenium concentration, initial pH, SO2 concentration and temperature etc. on the transformation of selenium species. It was believed that the application of ORP to the indication of selenite oxidation status needs further demonstration. Energy Dispersive X-Ray Spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) were used to confirm the migration of selenium in the desulfurization slurry to gypsum. In addition, DFT calculation was performed to obtain theoretical parameters for the adsorption of selenite and selenate by gypsum. The results of this study are helpful to understand the transformation and migration of selenium in the desulfurization system, which provide theoretical support for the realization of selenium in-situ control.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryPolyimide sponges have bright prospects in the weight reduction, heat insulation, and sound absorption equipment of aerospace, navigation, and other area due to their unique three-dimensional cellular structure and outstanding comprehensive performance. However, most polyimide sponges suffered from long and complex fabrication processes. Herein, an efficient and scalable approach, i.e. water-based foam forming, was proposed to fabricate ultralight and porous polyimide/aramid sponges (PASG). Attributed to the bubble-template nature of foam-forming, PASGs exhibit high porosity (>99%) and ultra-low density (～10 mg/cm3), and possess excellent thermal and sound insulation performance with an optimum thermal conductivity of 34.89 mW/m·K and noise reduction coefficient of 0.41. Besides, PASGs demonstrate outstanding mechanical properties after 500 compression cycles. This strategy providing more possibilities for developing the next generation of high-performance thermal insulation and noise reduction materials.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryHerein, we report multidimensional hybrid architectures wherein CoS2 nanoparticles are encapsulated in steam-activated reduced graphene oxide/carbon nanotubes (CoSx@srGO/CNT) for rechargeable Zn-air batteries. CoSx nanoparticles work as catalysts to grow CNT branches onto the srGO, and the CoSx@srGO/CNT act as bifunctional electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The bifunctional ORR and OER activities of the CoSx@srGO/CNT are substantially greater than those of CoS2, srGO, and CoSx@srGO as confirmed by onset potentials, Tafel and K-L plots, and mass activities. Zn-air batteries with CoSx@srGO/CNT catalyst achieved a specific capacity of 583 mAh·gzn?1 and maximum power density of 66.45 mW·cm?2, which are greater than Pt/C and IrO2 mixed catalyst, along with a long-term cyclability of over 100 cycles. The outstanding performance of CoSx@srGO/CNT is attributed to the abundant exposed active sites of CoSx on a unique 3D multidimensional graphene/CNT hybrid architecture and the rapid mass/charge transport for the enhanced bifunctional activities.
查看更多>>摘要：? 2022Although the selective catalytic reduction (SCR) of NOx is the most effective way to reduce related emissions, the V2O5-WO3/TiO2 catalyst which is most used for this purpose has a narrow operation temperature range of 300–400 °C and, therefore, has limited applicability. Hence, better catalysts with more abundant active sites and a wider range of acceptable temperatures (240–450 °C) are required, especially because heating at ≥350 °C allows for removal of ammonium sulfate, a catalyst poison that is formed during SCR. Herein, we aim to produce such catalysts by treating the TiO2 support with titanium isopropoxide (TTIP) at several TTIP/TiO2 mass ratios, as this treatment is expected to increase the number of catalytically active sites and facilitate the dispersal of active materials. The optimal performance, which was observed for the catalyst prepared at a TTIP loading of 5 wt%, was ascribed to the increased thermal stability caused by the high extent of W dispersion and the formation of V4+ by the reaction of V5+ with surface Ti3+. Therefore, these results pave the way for the fabrication of more efficient NOx removal catalysts.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryAlthough the effect of surface roughness on the floatability of a single mineral has been investigated extensively, a systematic study for the effect of surface roughness on the flotation separation of different minerals, e.g., flotation recovery, has never been dwelled. To fulfill this gap, in this study, the effect of surface roughness on the flotation separation of hematite from quartz was investigated with a series of experiments and detections. Micro-flotation experiments demonstrated that hematite particles with higher roughness resulted in higher recoveries for both hematite and quartz, but the improvement of hematite recovery was more significant, which promoted the flotation separation of hematite from quartz with a higher separation index (SI). Adhesion force measurements revealed that after interacting with 125 mg/L sodium oleate at pH 9, increasing nano-scaled roughness improved the hydrophobicity of hematite surface, and reduced the adhesion force of water droplet on hematite surface. Scanning Electron Microscope – Energy Dispersive Spectrometer observations confirmed that increasing nano-scaled roughness increased the number of fine quartz particles coating on hematite surface. Combined with the analysis of adhesion of water droplet and observation of fine particles coating on hematite surface, the effect of surface roughness on minerals flotation separation could be better understood.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryAs a way to valorise glycerol, the main by-product of biodiesel, this study is focused on the production of esters of p-methoxycinnamic acid and glycerol. These esters can replace hazardous octylmethoxycinnamate in the cosmetic industry, which is thought to act as an endocrine disruptor and can interfere with thyroid function. Several sulfonated mesoporous catalysts, with and without endcapping, were easily synthetized using several alcohols as porogens. These catalysts were characterized for structure and surface area, chemical composition and acidity, and tested under solventless conditions for the esterification of glycerol with p-methoxycinnamic acid. Their activity was similar to that of p-toluenesulfonic acid. The best catalysts for the reaction under study was the end-capped mesoporous solid prepared in isopropanol. Finally, the selected catalyst was tested in 9 runs conducted at 150–170 °C and at molar ratios glycerol:p-methoxycinnamic acid ranging from 3:1 to 9:1. The kinetic model that better fits to the experimental data comprises two esterification reactions in-series and a first-order catalyst deactivation. The activation energies were 87.33 ± 5.67 kJ mol?1 for the average esterification to the monoglycerides, 69.17 ± 9.84 kJ mol?1 in average for the reactions yielding the diglycerides, and 104.00 ± 15.30 kJ mol?1 for the catalyst deactivation.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryDevelopment of anode design is crucial for highly efficient and durable anion-exchange membrane water electrolysis (AEMWE) as the kinetic of oxygen evolution reaction (OER) is sluggish. In this study, a macroporous catalyst layer (macroporous_CL) was proposed as an anode design for AEMWE to enhance the catalyst utilization. A macroporous_CL contains pores of two main size ranges: hundreds of nanometers and hundreds of micrometers. It is prepared using a spraying method to form nanometer-sized pores. The use of a stainless-steel (SUS) porous transport layer (PTL) as the substrate of the spraying method produces micrometer-sized macropores. In an investigation of the effects of the macroporous_CL and conventional catalyst layer (plain_CL) on AEMWE using two different kinds of oxygen evolution reaction (OER) catalysts, the macroporous_CL exhibited higher performance with lower ohmic and charge-transfer resistances compared to the plain_CL. This performance enhancement was attributed to the improved catalyst utilization and electron transport. Also, the macroporous_CL showed better durability compared to the plain_CL. Therefore, the macroporous_CL has been considered as an alternative anode design for AEMWE.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryTrace amounts of pharmaceuticals and personal care products (PPCPs) are found in our water systems, and they are known to have adverse effects on wildlife and human at the ng/L to μg/L range, below the detection limit of most water analytical instruments. Methacrylate acid (MAA)-ethyl acrylate (EA) colloidal scaffolds were prepared via emulsion polymerization and used as templates for the in-situ co-precipitation of Fe2+ to produce stable functional magnetic nanoparticles (MNPs) (<500 nm) decorated with β-cyclodextrin (β-CD) (FMNP). Emulsion polymerization with the controlled addition of monomer mixtures allowed for good size control, and silica coating was introduced to prevent the oxidation of FMNP. The superparamagnetic FMNP with high saturation magnetization (33 emu/g) could be readily separated from water using a high gradient magnetic separator (HGMS). Procaine hydrochloride (PrHy) was used as a model pharmaceutical residue to evaluate the performance of the FMNP, and 53.65 mg PrHy/g FMNP was absorbed using 600 ppm FMNP. A fast (30 min) adsorption kinetic follows the Pseudo-first-order kinetic model that described the physical adsorption through a 1 to 1 host–guest inclusion mechanism. And the adsorption behavior followed the Freundlich isotherm with a linear adsorption performance. The proposed system is scalable and adaptable to existing water treatment processes, and it can be used for the detection of low concentration pharmaceuticals via a pre-concentrating strategy.
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Elsevier